Pump drain



Aprriiil 7, W6 B. R. MOBATH, JR

PUMP DRAIN Filed May 10, 1934 7'0 PWMP M01101? SWITCH INVENTOR A TORIVEY Patented Apr. 7, 1936 UNITED STATES PUMP DRAIN Bartley R. McBath, Jr.,

Montclair, N. 1., assignor to Worthington Pump and Machinery Corporation, New York, N.

Virginia Application May 10,

2 Claims.

This invention relates to centrifugal pumps and an object of the present invention is to provide means for automatically draining a centrifugal pump and its adjacent piping when the pump is shut down. I

Another object of the present invention is to provide draining means for a centrifugal pump which is automatically operated to drain the 'pump when it is shut down and operated upon starting of the pump to cut off draining action, which draining means is simple in construction and may be quickly and easily applied to centrifugal pumps of approved design.

With these and other objects in view as may appear from the accompanying specification, the invention consists of various features of construction and combination of parts, which will be first described in connection with the accompanying drawing, showing a pump drain of the preferred form, and the features forming the invention will be specifically pointed out in the claims.

In the drawing:

Fig. 1 is a side elevation of an automatic priming centrifugal pumping unit showing the improved draln applied thereto.

Fig. 2 is a detail section through a form of valve embodied in the drain.

Fig. 3 is a side elevation of a modified form of the invention.

Referring more particularly to the drawing, Fig. 1 shows a self-priming pumping unit of approved type embodying the driving motor I which is any approved type of electric motor and drives the centrifugal pump 2 which likewise may be of any approved type of centrifugal pump. In the construction shown in Fig. 1 of the drawing a vacuum or priming pump 3 is connected to the centrifugal pump 2 through the medium of the pipe or connection 4 for pumping air from the centrifugal pump 2 to prime the pump upon starting.

In some instances, pumps of this type are installed where they are apt to freeze, when shut down, and to prevent such freezing, means are provided for draining the casing of the centrifugal pmnp 2 and its discharge line 5, between the pump 2 and the check valve 6.' This draining means comprises a by-pass or drain pipe III which is connected to the lowermost portion of the easing of the centrifugal pump 2 and is shown in Fig. 1 of the drawing as connected to the suction pipe I.

A valve II of any approved type is plr ced in the by-pass or drain pipe It and is operated by a solenoid I2. The solenoid I2 is connected in circuit with the line I3 which supplies the energizing current to the motor I, between the control switch M and the motor so that when the control is opened to cut off the energizing of the motor, the energizing current to the solenoid it will Y., a corporation of 1934, Serial No. 724,885

also be out off and the valve I I will open to permit the draining of the water from the centrifugal pump 2 and a portion of its adjacent discharge line 5 back into the suction pipe I and from the suction pipe to the source of the supply of fluid being pumped.

The vacuum or priming pump 3 is of the type commonly known as water piston pumps wherein Water or other suitable liquid is employed as the piston in the pump, therefore this pump 3 must always containa quantity of liquid. To prevent the freezing of the water in the priming or vacuum pump 3, an electric resistance heating pad 20 is attached to the outer side of the casing of the pump 3. The heating pad 20 is connected by suitable wires 2! with the line current supply wires 22, beyond the switch l4. A thermostatic switch 23, of any approved type, is interposed in the line 2I and may be set to close the circuit to the heating pad 20 at any desired temperature so as to permit the heating of the pump 3 to prevent the freezing of the liquid therein.

In Fig. 3 of the drawing, a modified construction of the drainage system is shown. In this figure the pump 30 has a drain pipe 3| connected to the lowermost part of the casing of the pump which drain pipe connects to the suction pipe 32. A branch pipe 33 is connected to the drain pipe 3| and to the discharge pipe 34 of the pump beyond the check valve 35., A check valve 36 is placed in the drain pipe 3| so as to prevent pressure fluid from passing through the branch pipe 33 back through the pipe 3I into the pump casing 30. The solenoid operated valve 31 is interposed in the pipe 3| and is similar in construction to the solenoid operated valve II. The valve 31, like the valve II, is connected in circuit with the operating motor (not shown) for the pump 30 so that when the pump is shut down the valve 31 will open to permit the draining of the water from the pump casing and from the discharge pipe 34 of the pump.

The valves II and 31 are so constructed that when the respective pumps I and 30 are started the valves will be closed to cut off the draining action.

While in the drawing, the draining medium is illustrated as the pipe, it is to be understood that any suitable type of draining by-pass may be provided without departing from the spirit of the present invention.

It will be understood that the invention is not to be limited to the specific construction or arrangement of parts shown, but that these may be modified widely within the invention as defined by the claims.

What is claimed is:

1. In a pumping unit, the combination with a centrifugal pump, a vacuum priming pump for priming said centrifugal pump, and an oper- 60 ating motor for said pumps, of an electric heating pad attached to said vacuum priming pump and connected in circuit with the motor operating supply line, and a thermostatic switch in the connection between said heating pad and line for controlling the energizing of the pad.

2. In a pumping unit, in combination with a centrifugal pump, its operating motor and a vacuum priming pump for priming said centrifu- 10 gal pump, a drain pipe connected to the lower- 

